Thanks all. More detail and info to come after installation but quickly..
Today we managed to find and buy a new Bosch fuel pump in Bishkek that looks identical except for the part number. We have some concern about the fuel filter too though. We're wondering whether the filter might be choked on bad central asian fuel and whether this made the original pump struggle to the point of overheating. If the filter is bad then the new pump might fail quickly. So we bought a fairly generic fuel filter too. It may not fit in the OEM pump/filter/controller harness but if we have to punch a hole through the original filter material and add this new filter in-line outside the tank with some weird colostomy bag like hose hanging out until we can get to a BMW part then we might do this.